The present invention relates to a controller for an internal combustion engine that detects the temperature inside a combustion chamber.
For example, Japanese Laid-Open Patent Publication No. 2001-336468 discloses a device for detecting the temperature inside a combustion chamber. The device of the publication includes a glow plug, which is heated by supplying a current to a hot wire inside. The glow plug is attached to an internal combustion engine with one end exposed in a combustion chamber. The glow plug has a thermocouple located at a portion exposed to the combustion chamber. The thermocouple is configured to detect the temperature in the combustion chamber of the internal combustion engine.
In the above-described device, a thermocouple, which detects the temperature of the combustion chamber of the internal combustion engine, needs to be provided, which inevitably increases the costs.